In general, methods for purifying by removing foreign substances contained in air include a dry type method and a wet type method or a mixed method of a dry type and a wet type.
A representative example of the dry type method is a method which uses a filter.
However, in the case of the filter method, dust of fine particles is not completely collected and purified and, when a gas containing dust flows in, the dust is accumulated on the surface of the filter and dust-collection efficiency greatly deteriorates due to the blockage in the filter, and the filter may be a breeding ground for disease germs or germs.
Accordingly, there is a problem in maintenance accompanied by periodic replacement, and the non-woven fabric of the disused filter may generate secondary environmental pollutants and may be the main cause of environmental pollution.
In addition, as another dry type method, a gas purification device including photocatalyst, electrostatic precipitation, and plasma has been suggested. However, gas purification efficiency is low, and also, an anion-generating gas purification device is known as having a side effect of generating ozone which is harmful to human body health hygiene.
A centrifugal air purification device which is configured in such a dry type can achieve gas purification efficiency of 90-95% theoretically, but is not able to collect and purify dust of fine particles having a size of 5 or less, pollen, cigarette smoke, and harmful gas, which are harmful to human body health hygiene. Most of the air purification devices are manufactured for industrial use and thus their use is limited to simply removing dust in air by centrifugally separating the dust.
On the other hand, the wet type method is a method which induces a gas flow in a gas purification device and purifies a gas by using viscosity and adhesion force of water by bringing the gas into contact with a two-dimensional water film surface area.
However, there is a problem that only the pollutants of the gas in contact with the water film surface area are removed by using the viscosity and adhesion force of water, and most of the pollutants which are not in contact with the water film surface area are not removed. In addition, a gas containing excessive moisture is discharged, and thus there is a problem that a precision instrument is corroded.
From the perspective of aeromechanics, the ability of purifying fine dust smaller than 0.1 μm and air purification efficiency in the related-art wet type gas purification device are relatively high in comparison to the other types of gas purification devices, but the air purification efficiency is limited since it is less than 85% theoretically. In addition, the related-art wet type gas purification device does not have its own sterilization function for disease germs or microorganism, and thus may be a breeding ground for disease germs and is unsanitary. In addition, there is a problem that cleaning water is sterilized by treating with chemicals
In particular, the related-art wet type method has a problem that a purified gas and moisture are recombined with each other.
Referring to the related-art patent technologies, Korean Patent Publication No. 10-1994-0023518 discloses the feature of spraying moisture through a nozzle by using a pump, and discloses the feature of separating air and moisture without a pump, and Korean Patent Publication No. 10-2006-0055008 discloses the features of supplying washing water from a lower portion to an upper portion, and then scattering the washing water through three scattering means and bringing the washing water into contact with air moving up from the lower portion.
In addition, Korean Patent Registration No. 10-604643 (titled “Complex Air Purification Device”) discloses an air purification device which is configured to include a cleaning device for periodically cleaning the surface of photocatalyst, thereby increasing air purification efficiency and continuously maintaining a purifying ability, and furthermore, is able to separate and remove harmful elements such as fine dust by cleaning air using a water filter in parallel with the photocatalyst, and also, changes the suction and discharge directions of indoor air according to a condition, and diffuses and circulates stagnant air on an upper layer when the air purification device is driven by using an elevator type fan.